Deep beneath the frozen Arctic are deposits of methane. Lots of methane. And there's even more on the sea floor. As the environment warms, these deposits are being released into the atmosphere, presenting grave risks of runaway warming.

Deep beneath the frozen Arctic are deposits of methane. Lots of methane. And there's even more on the sea floor. As the environment warms, these deposits are being released into the atmosphere, presenting grave risks of runaway warming.